来自《耶鲁大学开放课程：基础物理 第9集 第9集》

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  and do the same thing;
  作相同的设定
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  but let's start with the simple thing.
  但让我们从简单情形开始
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  Here's a rigid body,
  这是一个刚体
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  three rigid rods with masses m1, m2, m3,
  三个刚性杆 物体的质量分别为 m1 m2 m3
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  and it's nailed here,
  在这端固定
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  and there is a skewer going through the board,
  这个有一个穿透黑板的钉子
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  and the things can only rotate around that.
  物体只能绕它旋转
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  By the way, I should tell you the convention for ω.
  顺便告诉你们关于 ω 的约定
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  In one dimensional motion,
  在一维运动中
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  velocity is positive, you're moving to the right,
  向右运动 速度为正
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  and negative you're moving to the left.
  向左运动 速度为负
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  With angular velocity,
  对于角速度